Biobanks containing formalin-fixed paraffin-embedded tissue, as well as frozen serum or plasma, are important resources for molecular epidemiologic studies. However, few studies have compared the reliability of formalin-fixed tissue samples and archival plasma samples for genotyping. We determined the genotype of four proposed genetic risk factors for hepatocellular carcinoma [hereditary hemochromatosis (HFE 63 and 282), alpha(1)-antitrypsin deficiency (AAT 342) and cystic fibrosis (CFTR 508)] on formalin-fixed tissue samples, stored for up to 25 years, from 318 patients diagnosed with hepatocellular carcinoma and on plasma or serum samples from 31 of these patients. The genotypes were analyzed by RFLP or allele-specific amplification as well as by TaqMan assays. In addition, genotyping was attempted after whole genome amplification by multiple displacement amplification (MDA). Genotyping was successful in 94% of the tissue samples and successful and identical to the tissue samples from the same subjects in 98% of the plasma/serum samples. DNA from plasma samples could be amplified >5,000-fold by MDA and genotyping after MDA gave identical results to the genotyping of the same subjects before whole genome amplification. MDA amplification of the tissue samples was not successful. In summary, archival plasma was found to be an adequate source of efficiently amplifiable DNA. MDA on plasma samples allows analysis of multiple genotypes in epidemiologic studies.
Serum samples from patients referred for liver biopsy for investigation of suspected chronic liver disease (n = 286) and from healthy middle-aged volunteers (n = 445) were analyzed for markers of exposure to GB virus C/hepatitis G virus (GBV-C/HGV), hepatitis B virus and hepatitis C virus. GBV-C/HGV analyses included GBV-C/HGV PCR for detection of viremia and GBV-C/HGV enzyme-linked immunosorbent assay for anti-GBV-C/HGV E2 antibodies. Liver biopsies were re-evaluated by a hepatopathologist. GBV-C/HGV markers were detected in 97/286 (34%) patients (GBV-C/HGV RNA = 26; anti-GBV-C/HGV E2 antibodies = 74) compared to 86/445 (19%; p < 0.0001) controls (GBV-C/HGV RNA = 7, anti-GBB-C/HGV E2 antibodies = 79). A significantly higher proportion of GBV-C/HGV-exposed subjects in the patient group were viremic compared to controls (27% vs. 8.1%; p = 0.0015). GBV-C/HGV markers were more commonly found in patients with chronic hepatitis B and C. In patients with GBV-C/HGV viremia, a higher occurrence of bile duct degeneration was detected than in non-viremic patients. Markers of GBV-C/HGV infection were over-represented among patients investigated for chronic liver disease, and ongoing GBV-C/HGV viremia was more common in this group than in controls. Apart from a higher prevalence of bile duct degeneration in viremic patients, infection with GBV-C/HGV did not confer any specific histological characteristics.
Background: Although abundant data are available regarding the prevalence of chronic hepatitis B or C virus (HBV, HCV) among both blood donors and patients with liver diseases, corresponding data for the general population are scarce. Accordingly, this study was designed to investigate the prevalence and clinical spectrum of HBV and HCV in a general Swedish middle-aged urban population. Methods: Demographic data and blood samples were collected from subjects enrolled in a prospective study of cancer development in the city of Malmö